The effects of feeding high fiber canola meal on total tract digestibility and milk production

Abstract

Two studies were undertaken to evaluate the nutritive value of high fiber canola meal (HFCM) relative to regular canola meal for ruminants. In the first study, 21 growing lambs were utilized in a randomized complete block design to determine the total tract digestion coefficients of dry matter (DMD), crude protein (CPD), gross energy (GED), neutral (NDFD) and acid (ADFD) detergent fiber and the digestible energy (DE) contents of seven dehydrated alfalfa-based diets containing 0, 250, 500 and 750 g kg−1 HFCM or canola meal. In the second study, the effect of feeding HFCM as a protein supplement to dairy cows relative to canola meal and soybean meal (SBM) was examined in a triple 3 × 3 Latin square design. Results of the first study showed that HFCM had lower (P < 0.05) DMD, CPD, GED and DE contents than canola meal. The estimated DMD, CPD and GED and DE contents for HFCM were 674 and 795 g kg−1, 695 kJ MJ−1 and 13.68 MJ kg−1, respectively. The corresponding values for canola meal were 707 and 841 g kg−1, 727 kJ MJ−1 and 14.10 MJ kg−1, respectively. Results of the second study showed that protein supplement source had no effect on DM intake, milk yield, milk fat g kg−1, lactose g kg−1 and total solid g kg−1. However, cows fed HFCM- and canola meal-based diets produced milk with lower (P < 0.05) protein content than those fed the SBM-based diet. It was concluded that HFCM had lower total tract nutrient digestion coefficients and DE content compared with canola meal. Incorporation of HFCM in dairy rations up to 100 g kg−1 of the ration had no adverse effect on milk yield or milk composition compared with canola meal. Key words: High fiber, canola meal, total tract digestibility, lactation